Electrical breaker



March 8, 1949 c. L. Hu slcKER' ELECTRICAL BREAKER Filed July 12, 1946 4F IE: .E

'INVENTOR C /gd Lhunsickzr- BY ATTORNEY Patented Mar. 8, 1949 UNITEDSTATES PATENT OFFICE ELECTRICAL BREAKER Clyde L. Hunsicker, SanFrancisco, Calif. Application July 12, 1946, Serial No. 683,021

Claims. 1

This invention relates generally to the construction of electricalcircuit breakers of the type applicable to internal combustion engines.In general such breakers perform the function of making and breaking thebattery or low tension circuit incorporated in the ignition system ofthe engine.

It is well known that the breaker assemblies used in conjunction withgasoline and other types of internal combustion engines require frequentajustments between the contacts, if the electrical ignition system ofthe engine is to be kept operating at optimum efliciency. One of theprincipal causes which contributes to misadjustment between the contactsis wear between the rocker arm carrying the movable breaker contact, andits associated operating ca m.

It is an object of the present invention to provide breaker means of theabove character having provision for automatically adjusting orcompensating for wear between the rocker arm and its associatedoperating cam, thus eliminating or minimizing the necessity of makingmanual adjustments of the contacts.

More specifically it is an object of the invention to provide breakermeans of the above character having the main rocker arm carried by asupplemental compensating arm, with the latter arm being arranged andserving to compensate for wear between the main rocker arm and itsassociated cam.

Additional objects of the invention will appear from the followingdescription in which the preferred embodiment has been set forth indetail in conjunction with the accompanying drawing.

Referring to the drawing:

Figure 1 is a top plan view of a breaker incorporating the presentinvention, and intended in practice to be used with additional parts ofan electrical distributor.

Figure 2 is a side elevation in cross section taken along the line 2-2of Figure 1.

Figure 3 is a detail in section illustrating the rubbing blocks of thetwo arms and the members with which they engage.

The embodiment of the invention illustrated in Figures 1 to 3 consistsof a shaft I0 which extends through a suitable support I I. In aconventional installation the shaft I0 is driven through suitablegearing from the crank shaft of the internal combustion engine.Supporting means I I is a part of the housing of the electricaldistributor, and is customarily made of suitable molded insulatingmaterial, such as a phenolic condensate product. The shaft [0 carries acam member I2 having a cam surface depending upon the type of enginewith which the device is to be used. In a typical instance where thedevice is used with a six cylinder gasoline engine, the periphery of cammember I2 is hexagonal as illustrated. Mounted upon the shaftimmediately below the cam member I2 there is a second member I3 which iscylindrical shaped, and which is for a purpose to be presentlydescribed.

The electrical contact i4 is mounted upon one end of the manuallyadjustable screw it, which in turn is carried by the supporting standardI1. Contact I8 which cooperates with contact I4 is carried upon one endof the rocker arm [9. Intermediate its ends rocker arm [9 has rubbingengagement with the surface of cam member I2, and for this purpose thearm is provided with a suitable rubbing block 2|, which can be formed ofsuitable material such as hard fiber or composition.

Below the rocker arm I9 there is a second compensating arm 22. One endof arm 22 has a pivotal connection 23 to the fixed support II. The axisof this pivotal connection is preferably in the proximity of thecontacts I4 and I8, as illustrated in Figure 1. Intermediate its endsarm 22 is likewise provided with a rubbing block 24, which engages thecylindrically shaped member I3. The other end of arm 22 has a pivotalconnection 26 with the corresponding end of the rocker arm I9. Asuitable insert rib 21 is shown carried by the support II for thepurpose of underlying and supporting the arm 22 as illustrated.

Both of the arms I8 and 22 are urged toward the members I2 and I3 by thetension spring 28. One end of this spring is attached to an ear 29formed on the rocker arm I9, and the other end is attached to ananchoring stud 3|, which in turn is carried by the support I I.

In accordance with conventional practice the upper end of shaft I0 isshown provided with a slotted portion 32 which receives the conventionalhigh tension distributor arm.

The device described above is intended to be connected in the ignitioncircuit of an internal combustion engine, as for example an automotivegasoline engine, whereby the breaker contacts M and I8 make and breakthe battery or low potential circuit of a high tension ignition coil.The distributor customarily associated with my device distributes highpotential from the coil secondary to the spark plugs or like ignitiondevices of the engine.

Operation of the breaker means described above is as follows: Duringnormal operation of the engine, shaft i is rotating at a proper speeddetermined by the speed of the crank shaft of the engine, whereby cam I2operates the rocker arm If) to make and break the contacts l4 and i8.Rocking movement of arm 19 is accommodated by pivotal movement about theconnection 26. Spring 28 not only urges the rocker arm 19 toward the cammember I2, but also urges the compensating arm 22 toward the cylindricalshaped member 13. Members l2 and iii are made comparable as to diameterand circumferential extent, and their surfaces are made of comparablematerials and finish whereby the rates of wear between these members andthe rubbing blocks 2| and 24 are comparable. It will be evident that anywear between the block 2! and cam member l2 tends to cause misadjustmentbetween the contacts l4 and I 8, assuming that the axis of connection 26remains stationary. However with comparable wear taking place betweenthe block 24 and member I3 as wear proceeds the axis of pivotalconnection 2'6 is gradually shifted on the arc of a circle havingpivotal connection 23 as its center. Such movement of the pivotalconnection 26 therefore compensates for wear between block 2| and cammember l2, and tends to maintain the adjustment between the contacts 34and I8 substantially the same irrespective of wear. As a result therequirements for manual adjustment of the stationary contact M, byturning screw I 6 manually, are greatly reduced or eliminated entirely.This in turn makes for max imum performance and efficiency of theengine, because misadjustment of the contacts necessarily interfereswith timing of the engine and makes for loss of efiiciency.

I claim:

1. In electrical breaker means for application to the ignition system ofan internal combustion engine, a shaft adapted to rotate, a stationarysupport through which the shaft extends, a cam member formed on theshaft, cooperating movable and stationary electrical contacts, means formounting the stationary contact on the support, a rocker arm having oneportion of the same in rubbing engagement with the cam member, themovable contact being mounted on one end of the arm, and meansinterposed between the support and said arm serving to automatically andsubstantially completely compensate for wear between the arm and saidcam member.

2. In electrical breaker means for application to the ignition system ofan internal combustion engine, a shaft adapted to rotate, a stationarysupport through which the shaft extends, a cam member formed on theshaft, cooperating movable and stationary electrical breaker contacts,means for mounting one of the contacts on the support, a rocker armhaving one portion of the same in rubbing engagement with the cammember, the movable contact being mounted on one end of the arm, andWear compensating means pivotally connecting the other end of saidrocker arm to said support, said wear compensating means serving toautomatically shift said point of pivotal connection of the rocker armduring usage of the device.

3. In electrical breaker means for application to the ignition system ofan internal combustion engine, a shaft adapted to rotate, a stationarysupport through which the shaft extends, a cam member formed on theshaft, cooperating movable and stationary electrical breaker contacts,means forming a mounting for the stationary contact, a rocker arm havinga portion of the same intermediate its ends in rubbing engagement withthe cam member, the movable contact being mounted on one end of the arm,a supplemental circularly contoured rubbing surface formed on the shaftadjacent the cam member, a second compensating arm disposed adjacent therocker arm, said second arm having a portion of the same intermediateits ends in contact with said rubbing surface, a pivotal connectionbetween the other end of the rocker arm and one end of the last namedarm, and a pivotal connection between the other end of the last namedarm and said support, said last named pivotal connection t being in theproximity of said breaker contacts,

and spring acting between the support and said rocker arm serving tourge both said arms into rubbing engagement with said cam member andsaid rubbing surface.

4. In electrical breaker means for application to the ignition system ofan internal combustion engine, a shaft adapted to rotate, a stationarysupport through which the shaft extends, a cam member formed on theshaft, a circularly contoured member formed on the shaft adjacent saidcam member, said members having surfaces of comparable circumferentiallength and wearing characteristics, cooperating movable and stationaryelectrical breaker contacts, means for mounting the stationary contacton the support, a rocker arm having a rubbing block intermediate itsends, the other of said contacts being mounted upon one end of said arm,said rubbing block having rubbing engagement with said cam member, asecond compensating arm, said compensating arm having a second rubbingblock intermediate its ends and having rubbing engagement with theperiphery of said circularly contoured member, both said blocksaffording substantially equal contact areas on said cam and circularmembers, means forming a pivotal connection between one end of saidcompensating arm and said support, the axis of said pivotal connectionbeing located adjacent said breaker contacts, means forming a floatingpivotal connection between the other end of the rocker arm and the otherend of said compensating arm, and spring means serving to urge saidrubbing blocks with equal forces into engagement with the surface ofsaid cam member and the periphery of said circularly contoured member.

5. In electrical breaker means for application to the ignition system ofan internal combustion engine, a shaft adapted to rotate, a stationarysupport through which the shaft extends, a cam member formed on theshaft, a circularly con toured member formed on the shaft adjacent saidcam member, said members having surfaces of comparable circumferentiallength and wearing characteristics, cooperating movable and stationaryelectrical breaker contacts, means for mounting the stationary contacton the support, a rocker arm having a rubbing block intermediate itsends, the other of said contacts being mounted upon one end of said arm,said rubbing block having rubbing engagement with said cam memher, asecond compensating arm substantially coextensive with the first arm,said compensating arm having a second rubbing block intermediate itsends and having rubbing engagement with the periphery of said circularlycontoured member, both said blocks affording substantially equal contactareas on said cam and circular members, means forming a pivotalconnection between one end of said compensating arm and said support,

the axis of said pivotal connection being located REFERENCES CITEDadjacent said breaker contacts, means forming a floating pivotalconnection between the other end The following references are of recordin the of the rocker arm and the other end of said comfile Of this p ntpensating arm, and a single spring connected to 5 v UNITED STATES PATENTthe first named arm at a point between the rubs bing block of the sameand said floating pivotal Number Name Date connection and also connectedto the support, 9 9 Irgens P 1933 said spring serving to urge both saidblocks with equal forces against the surfaces of the cam and 1 circularmembers and serving to urge the movable contact toward the stationarycontact.

CLYDE L HUNSICKER.

